Concurrent malignant melanoma and cutaneous involvement by classical Hodgkin lymphoma (CHL) in a 63 year-old man

Secondary skin involvement in classic Hodgkin lymphoma: Results of an international collaborative cutaneous lymphoma working group study of 25 patients

BACKGROUND

Cutaneous involvement by classic Hodgkin lymphoma (CHL) is an extraordinarily rare phenomenon in the current era. To date, no single large case series of cutaneous involvement by Hodgkin lymphoma has ever been reported in the literature.

METHODS

A comprehensive search for cases designated "skin" and "Hodgkin" was performed at different institutions between 1990 and 2020. Twenty-five cases were identified, and each case was independently reviewed by at least three board-certified dermatopathologists and/or hematopathologists.

RESULTS

All cases represented examples of systemic CHL with secondary skin dissemination. A single lesion, usually a tumor, nodule or infiltrative plaque was observed in 56% of cases and multiple lesions were present in 28% of cases. Most patients (86%-12/14) had a diagnosis of stage IV disease at first diagnosis. The interval between the clinical (first) diagnosis of HL and the development of skin lesions ranged between 6 and 108 months (average 33.75 months). Comprehensive histopathologic evaluation of these cases (at the initial diagnosis) revealed a diagnosis of classic HL not otherwise specified (NOS) in 60% of cases (15/25), nodular sclerosis type in 24% (6/25), mixed cellularity in 12% (3/25), and lymphocyte depleted in 4% (1/25).

CONCLUSIONS

We provide documentation of a large series of CHL with secondary skin involvement in association with CHL with additional clinical, morphologic, and immunophenotypic features.

Mummified Cells are a Common Finding in Cutaneous Hodgkin Lymphoma and Can Be Used as a Diagnostic Clue

Specific cutaneous involvement in Hodgkin lymphoma is rare. In cutaneous lesions, the diagnosis is usually based on the recognition of diagnostic Reed-Sternberg cells and its variants. In nodal Hodgkin lymphoma, so-called mummified cells (cells with condensed cytoplasm and pyknotic eosinophilic or basophilic nuclei) are often seen. They are sometimes conspicuous and easy to recognize, thus serving as a clue to the diagnosis. Our objective was to study cases of cutaneous Hodgkin lymphoma to identify the occurrence of mummified cells. We studied 12 patients (4 women and 8 men; age range 23-80 years). In 6 patients, cutaneous and extracutaneous disease was identified almost simultaneously; in 4 patients, lymph node disease preceded cutaneous involvement; and in the remaining 2 patients, the skin lesions were the presenting sign, whereas lymph node involvement occurred later. Histopathological, immunohistochemical, and molecular-genetic studies, including rearrangements for TCR, IgH genes, and PCR for EBV, were performed. Cutaneous biopsy specimens revealed either a multinodular or diffuse infiltrate, included small lymphocytes, eosinophils, plasma cells, and macrophages, but in all cases, diagnostic Reed-Sternberg cells and its variants were identified. Mummified cells were detected in 9 cases, either as occasional scattered mummified cells often requiring a search (6 cases) or being conspicuous, grouped and therefore easily identified (3 cases). Immunohistochemically, in all 7 cases studied, mummified cells were positive for both CD30 and CD15. It is concluded that mummified cells are encountered in a majority of cases of cutaneous Hodgkin lymphoma.